Bull Run vs Manassas
This hand-drawn map of the Battle of Bull Run is on display at the Manassas National Battlefield Park. As far as artifacts go it is fairly standard. A participant of the battle recreated the battlefield on paper. Possibly as part of an after-action report, or maybe just so they would not forget. We don’t know about the author, but we know one thing for sure. The person who made the map was from the Union.
How do we know? The title on the map is Battle fo Bull Run. Had it been a Confederate that drew the map most likely it would have been labeled Battle of Manassas. During the war, the Union Army tended to name battles after the closest body of water. The Confederates used the nearest town.
Some other examples are:
The battle fought between April 6 and 7, 1862 is known in the North as Pittsburg Landing, but in the South, it was called Shiloh.
September 17, 1862, found the north fighting the Battle of Antietam, but the South fought the Battle of Sharpsburg.
April 8th, 1864 was the Battle fo Mansfield to the Confederates, but to the Union, it named Sabine Cross Roads.
Of course, in the end, the name of a particular battle was usually determined by the winner. Today, especially if you visit the national parks that have sprung up around the former battlefields you may recognize most of the ones in the South will use the Southern names.
As for why they were named as such, one historian theorizes that since many Northerners were from cities they considered bodies of water as the more noteworthy geographic feature. Southerners, however, tended to be more rural so they regarded towns as most noteworthy.
So if you are discussing the Civil War with someone pay attention to how they refer to battles, it may give you some insight as to where they are from!